69 terms

GEOSCI 040 Midterm 2

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Terms in this set (...)

In relation to waves, H stands for...?
Wave height (in meters)
The distance from the crest to the trough
In relation to waves, L stands for...?
Wave length (in meters)
In relation to waves, S stands for...?
Wave speed (in meters/second)
In relation to waves, T stands for...?
Wave period (in seconds)
The time it takes for one wavelength to pass
In relation to waves, d stands for...?
Depth of water column (in meters)
In relation to waves, n stands for...?
Water surface displacement from the Still Water Level (SWL)
SWL is a reference point, or the ocean without any waves
How can you tell if a wave is a deep water wave?
The depth is much greater than the wavelength
d > L/2
How can you tell if a wave is a shallow water wave?
Depth is significantly less than the wavelength
d < L/20
Speed of a deepwater wave is directly related to...?
Speed is related to the Period (T)
Linear relationship
S = 1.56(T)
How is wavelength related to the period of a wave?
They are exponentially related
L = 1.56(T)^2
What are the three major factors that influence speed, wavelength, and period of a wave?
1. Strength of the wind
2. Wind duration (how long it blows)
3. Fetch (distance of the region across which it blows)
What is the highest confirmed wave height?
34 meters
What can be observed when waves "break"?
Whitecaps
Waves cannot build to more than ______ of their wave height.
1/7 of their wave height
For shallow water waves approaching the shore, what happens to the wavelength, celerity (speed) and period?
Wavelength and celerity DECREASE
Period remains CONSTANT
When does a shallow water wave break?
When the wave height is 3/4 of the water depth
What is the formula to find the speed of a shallow water wave?
S = (the square root of) g x d
where g = gravity (9.8) and d = depth
Waves that travel as groups across long distances are called...?
Wave Trains
Does the front wave of a wave train remain the front wave during its travel?
No, the front waves continually die out because of the energy required to "spin up" water through which they pass. The second wave then takes its place.
Constructive wave interference can be defined as...?
Waves interact to build crests or troughs that are higher or deeper than the original wave
Destructive wave interference can be defined as...?
The waves cancel each other out.
Define Flood and Ebb.
Flood - Rise of water level
Ebb - Fall of water level
What is a semidiurnal tidal regime?
Goes through approximately two wave cycles a day
12 hours and 25 minutes per cycle
Example: East Coast of the U.S
What is a diurnal tidal regime?
One full tidal cycle per day (or per 24 hours and 50 minutes)
Example: Gulf Coast of the U.S
What is a "Mixed Tide?"
Usually goes through two tidal cycles a day, but can vary
Example: U.S Pacific Coast
In reference to tides and tidal cycles, what is the range?
The difference between high and low water level
Spring tides occur during...?
1. Full moon
2. New moon
3. March only
4. 1 & 2 above
5. Quarter moon
4. 1 & 2 Above (Full Moon and New Moon)
What are the two factors that determine the tides?
1. Gravitational Forces (Mostly the Moon, but also the Sun)
2. Inertial (Centrifugal) Forces, i.e the motion of the Earth
**These two forces are equal and opposite forces!
The highest highs and the lowest lows are associated with what kind of tides?
Spring Tides
**The sun and the moon are working together
When the sun and moon are pulling the water in opposite directions, this type of tide occurs.
Neap Tides (Weaker Tides)
First quarter and third quarter moons are associated with what kind of tides?
Neap Tides
Amphidromic points are...?
Point around which the tides rotate
There are 12 different points on Earth
They have to rotate around these points because the land prohibits them from following the moon
Coral do best in:
A. clear, cold, shallow waters in the Polar Seas
B. areas of low levels of nutrients
C. deep water, below the photic zone
D. water with abundant sediment and outwash from local rivers and streams.
E. all of the above
B. areas of low levels of nutrients
Which of the following is true about spawning
A. catadromous fishes use gills for gas exchange, whereas anadromous fishes do not.
B. anadromous fishes spawn where they normally live.
C. anadromous fishes migrate from saltwater to freshwater to spawn.
D. catadromous fishes migrate from pelagic zones to beaches to spawn.
E. none of the above
C. anadromous fishes migrate from saltwater to freshwater to spawn.
Marine fishes drink seawater, freshwater fishes do not drink water. A) True B) False
A). True
Which option makes the following a true, complete sentence. Eutrophication causes dissolved oxygen levels to be __:
A. high in the winter, in part because bacteria migrate south in winter
B. high in the winter, in part because sunlight is stronger in winter
C. low in the summer, in part because thermal stratification is greatest in summer
D. low in the summer, in part because thermal stratification is weakest in summer
E. none of the above
C. low in the summer, in part because thermal stratification is greatest in summer
Hypoxia is primarily caused by strong winds, which blow away the clouds. A) True B) False
B) False
Sharks, skates and rays are all in the Class Chondricthyes, or cartilaginous fish.
A) True B) False
A) True
Which is/are true about the cycle of Eutrophication
A. excess nutrients support blooms of phytoplankton and other microscopic plants
B. sinking organic matter is decomposed by bacteria, which release nutrients that are cycled back to the surface, thereby producing more organic matter
C. concentrations of dissolved oxygen become very low because the bacteria that thrive on organic matter use the oxygen.
D. if the water column does not mix, for example because of seasonal thermal stratification, oxygen concentrations in the bottom waters can become so low that nothing can live.
E. all of the above
E. all of the above
Fishes:
A. are typically cold-blooded vertebrates with scales, gills and fins
B. in some cases do not have scales
C. in some cases are warm-blooded, meaning they can control their body temperature
D. all of the above
E. none of the above
D. all of the above
Excess nutrients in the Chesapeake Bay watershed come primarily from:
A. agricultural practices such as overfertilization
B. near shore wave action
C. the gulf stream
D. all of the above
A. agricultural practices such as overfertilization
Branching Corals spawn at night by releasing eggs and sperm into the water column to what advantage?
A. to synchronize spawning over a reef to guarantee survival of many eggs/larvae.
B. to provide a larger gene pool for fertilization to guarantee health of the population.
C. to avoid predation of eggs & larvae by fish feeding mainly in daylight
D. all of the above
E. none of the above
D. all of the above
Which of the following is/are true?
A. aquaculture represents a substantial and growing part of world fish production
B. world fish production has increased steadily for the past 50 years and advances in large-scale fishing techniques will likely allow fish catch to increase for another 50 years
C. in the World ocean, large fish are present in the same numbers today as they were 50 years ago
D. total world fish production includes fish that are caught for human consumption and for industrial, non-food, uses
E. A and D
E. A and D
State College is part of the Mississippi river watershed and rainwater that flushes fertilizers into the local rivers contributes to the Dead Zone in the Gulf of Mexico. A) True B) False
B) False
Industrialized fishing is one of the main causes of overfishing in the ocean. A) True B) False
A) True
Coral reef health is increasingly threatened by
A. viral and bacterial infections
B. nutrient surplus leading to excess algal growth
C. effects of overfishing in reef settings
D. increasing carbon dioxide in the atmosphere
E. all of the above
E. all of the above
Aquaculture, while having the potential to supply protein to a burgeoning world population, is plagued by which of the following problems:
A. lack of suitable species to raise
B. lack of sustainability because of inefficiency in feeding
C. lack of demand by consumers
D. lack of seawater of suitable salinity & temperature
E. all of the above
B. lack of sustainability because of inefficiency in feeding
Modern coral reefs appear to be limited to regions where the
A. salinity is between 10 and 25 o/oo
B. concentration of particulates is high
C. mean annual temperature is >20°C
D. water depth is greater than 100 meters
E. none of the above
C. mean annual temperature is >20°C
The Cod fishing industry is doing very well, because Cod is plentiful and has never been over fished. A) True B) False
B) False
When coral bleaches white, this indicates that
A. it is healthy
B. it is preparing to release its eggs
C. the polyp has recently split into two
D. it is preparing to attack its nearest neighbor
E. none of the above
E. none of the above
Corals:
A. photosynthesize carbohydrates
B. consume C02 and large fishes
C. get over 95% of their food from algae that live within them
D. do best in reefs with many Crown-of-thorns starfish.
E. none of the above
C. get over 95% of their food from algae that live within them
Fish with long life spans are not a sustainable fishery resource because of
A. their small body weight at adulthood
B. their tough musculature
C. their ability to avoid nets and hooks
D. their slow reproductive rates
E. none of the above
D. their slow reproductive rates
Lateral line organs are used by fish to
A. extract dissolved oxygen from water
B. remove carbon dioxide from the bloodstream.
C. detect predators and other fish.
D. all of the above
E. none of the above
C. detect predators and other fish.
What did Jeremy Jackson argue is the worst kind of pollution?
A. oil spills
B. chemical spills
C. plastics
D. biological pollution (nutrients and invasive species)
E. rubber duckies and sneakers
D. biological pollution (nutrients and invasive species)
Hypoxia is caused by and exacerbated by
A. eutrophication
B. stable stratification of the water column
C. over sedimentation, which kills marine plants
D. all of the above
D. all of the above
Which of the following would help reduce agricultural runoff of nutrients to streams and rivers?
A. developing wetland or riparian buffers along streams
B. increase forested area at the expense of croplands
C. adoption of best practice methods of tilling and fertilizer application
D. all of the above
D. all of the above
Waves would like to directly follow the gravitational pull of the moon, but instead are trapped by...
1. The continents
2. The Coriolis Effect
In the Northern Hemisphere, tidal crests move in a...
Counter-clockwise motion
What is a node?
A fixed point in the center of an amphidromic circulation
How often does one amphidromic cirulation make a complete rotation?
12 hours and 25 minutes
Where are the highest tides in the world?
The Bay of Fundy
The tidal range toward the center of an amphidromic system is ____ the range at the edges of the system.
1) of longer duration than
2) larger than
3) about the same as
4) smaller than
5) none of the above.
4) smaller than
What are some inputs that contribute to the beach's sand?
Longshore Transport
River Supply
Cliff Erosion
Onshore Transport
What are some outputs that contribute to the beach's sand budget?
Longshore Transport
Offshore Transport
Wind transport of dunes
In relation to the beach's sand, what is acretion?
The building of the shore
In relation to the beach's sand, what is erosion?
The wearing down of the shore
A steady state of beach sand is where...
Inputs=Outputs
What is the difference between summer and winter beach profiles?
Berm in the summer means high volume
Flat in the winter means low volume
**Seasonal cycle, it grows and shrinks every year
What is a rip current?
A strong offshore directed current, usually 10m wide, that transports sand offshore rapidly